1. Field of the Invention
This invention relates generally to drilling boreholes and in particular to a method and apparatus for geosteering the drilling of boreholes in three dimensions. Still more particularly, the present invention relates to a computer implemented method, apparatus, and computer usable program code for real-time geosteering in three dimensions.
2. Background of the Invention
As the demand for energy grows, pressure mounts on companies to extract as much hydrocarbon as possible from reservoirs. In other words, the oil industry is under pressure to improve recovery factors. One key element that is fundamental in achieving higher recovery factors from reservoirs is to improve the net-to-gross ratio of horizontal wells. Currently, improving this ratio can only be accomplished by increasing the success rate in making reservoir contact while drilling wells.
Traditionally, the steering of horizontal wells has been based on logging-while-drilling measurements (LWDs). These types of measurements rely on sensors to measure the characteristics of the different formations when drilling through those formations. This information is used to make the correct steering decision. The steering of wells based on real-time formation evaluation data is referred to as geosteering. This type of geosteering is currently a reactive process. As a result, if the measurements indicate that an undesired formation has been reached, the borehole has already entered that formation. For example, in drilling a borehole, it is desirable to drill through sand as opposed to shale. Using logging-while-drilling measurements may result in the borehole exiting the sand and entering a shale formation.
Therefore, it would be advantageous to have an improved method, apparatus, and computer usable program code for geosteering in drilling boreholes. In particular, it would be advantageous to have a method and apparatus that allows decisions to be made to avoid undesired formations before those formations have been reached in drilling the borehole for a well.